SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e91d2f0733fd135fafd2e2b454656cb094c01190a334a343dc5d59e1ab5c6c47' 
  AND token = '4jVBKfYooXnxqDAq4gdI5nyKlocyIWne7caG13qmc4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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