SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae996f3b14e2177ebb4c006186f04a0eba3850f4e088e6a85f9aa6d78b7f2fd1' 
  AND token = 'u9L3XC+0X6SDOVFkb4mfg0g3IgHVJJdnDZPhShoyRlc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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