SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9e1dfcf70fd17ce7001519ccc858a47f88e1b6bad86f3f21c914bb06a8cecc59' 
  AND token = 'snDOLBNrxzdefGF8u/W2lsJWdE6Jxpvs7H/rBzkItxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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