SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd370baacddbd2f4396aa753f64126e53f659309a511ef8012470e3cf12388c42' 
  AND token = 'RCTvKEZhYdvW6ZHc+5dC/Lk/YJb+UJl8+3grhd4z80c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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