SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b211aa516fc567bf9ff54f4a9e05dec5db11ffb3136d939a124cf1d525e161f' 
  AND token = 'FBgVhEte+629ZZnCL+KopdlUIjdabg8OuKEPiU3GOSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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