SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60b929d59a301256bd17fdcc7b9484f1176b3c41bcdba8922632c5c2967502aa' 
  AND token = 'B7SqsipjOLQC3ObzEwOzx47ZLkAz2n4LgmQ/RxFVGRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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