SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8ecd057978eb43f5a7fffcbeb99e8082f36c5bdc416ec1f12c38536c87f2133' 
  AND token = 'Q68St143AJ/xdu5g5X/cgZ5jtkmLXFAzWYgmy8FRoS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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