SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c07121a6e437c5734a874c1f65979758dbcc73c5fe9e0b8f1692afe9130d840b' 
  AND token = '5I7YJBlQZSqGS16gJJY1SBn32sKj+WmW7ic9EFecgbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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