SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dfc9c3184be4c53da3cc1dfed978878404180c209c8c5139282574eb9138035' 
  AND token = 'mB90JKwfWnaRY/DVRPU1WqFkqpHg1RBJeBG9bOPJRCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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