SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a66275f095726fa0fad0f206ed1909f635e2cebe497abc29766f8f01db8c7711' 
  AND token = 'oMt9G6gz/GdjYwtepqGWKOKPAs4WXpCcrqyLJN/jJH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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