SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '969879436f9c1d8adc81b550697990ff427c31d7512d38b4bffc59e4ff2d48ee' 
  AND token = '0IS0fTUUkbyqPWypJMfepcugwQ42DP6ef+Az3vW20Sw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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