SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '893f6443b7deb4b7fe3e4489433b1590d4340c31f2e6157d6748802047e2d494' 
  AND token = 'ZezwxEth5scLDYVtFcW+nMVORjGLBWnBQPdgnUk2ulM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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