SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05d1916034e363a78d4469c69abfa382cfddd21ad24f3a6c927a5753401c5d94' 
  AND token = '9hpP+gWA4YWZxf/Z9u8ytw/ONlJdAT57kZ2ZNBWlSEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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