SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6772c51d657095e6cc48c972cfff4b8597a94b6a6ffdda763da99807d2df71f0' 
  AND token = 'iMeUaDrRBPQRYEbYwfTjniUyzkaZ/lC95+3NeLXQTcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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