SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e83638b1ac5a0a469917e1715287adeaffc78a7b995a71d34daa840ba35578a' 
  AND token = 'oiikVvNI1B1O6btCL+8XJO7BFQUp8jq6l995kNEiHDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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