SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e59bc36713604c52635e7c791c2651dbcb95a1a405dffbe7a17373a88ab7db73' 
  AND token = 'jYCpJdnBHMweOVGqWdk5VtBXyTW31gF375DmQKgGy1k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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