SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ced0b4d22ce61ee39f048769015041b6765b13d01364c8463157da1909f2d746' 
  AND token = 'W1CAVHhhUNoDjtKkzLwJyNkYks5Zq1NgE+/XON/kGPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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