SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a757b395389900110f5684e1e10e303cf2525af8e68d67b58233d00014b621f5' 
  AND token = 'KTt+GY84WFpgubK1PbhktNbbAtwMDvdMeIhRbRdsym4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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