SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9e57502636eb780efc25678ad13899976e84fa75e378d1082bb8a5e98d8316c' 
  AND token = 'yaqLbmuzFFYWSS33Jl6SCmvQjJI3NIVjPgGX0pybhds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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