SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '853c78de06f60c68177d859300898bea530ffea205829e506f4a506c92d4d9c0' 
  AND token = 'eL9/37J5nKZ6FZQup+RbYIQxyLtnHGQaP5uzjAxURwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}