SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be58a9a652a322d9349e329130a31d55311442dc4eef86f6ae97edac704c4039' 
  AND token = '4L5d8NBYKIRdbTWV1BI8Nl161IHo8Bp1aYo83nFG2TQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}