SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4af2c47327e7528a2a9653e51aab593a314b794c1a7639836c855cf8c07f91ca' 
  AND token = 'bGKrSwXzR0tE4vuT4Yjafs5L7cE2d2KZeu/0q7BID2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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