SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb50c52b7dae8166826fbde73d803093b1773c3fe1ca57a074cf023160ab5f56' 
  AND token = 'hO4Zn3H8PeQS8WL/qMBBNPEtDCHQ6yRhNghvGyBvZjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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