SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fb4290e17fa432b0a321a1e89a054f2890e56c8e5b39838475e8cc45eadd917' 
  AND token = '5TZVZ408Fx1xp6/XIIKohGLbdg5pB1iXlFSNqJWYhD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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