SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e102b33d250bd11b638aabe006581b94ec12be0921e1f3a671195c045edafbf2' 
  AND token = 'pCDEab5lGuxEJ9VcCmQh2qQdpKN5KNDyZ2SvmGJLhcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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