SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e582a809246a0d7ef15c3f5072cda3262434b84f24b101b0611fb106eaad4d8' 
  AND token = 'uF6VhBkExnKnkvLShRBBJIZLdDGWsk/pWNoHZa4TRYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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