SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fca0b8125058207305d8f65308c309ef14729bf2a517178aa7f3c0efa8488887' 
  AND token = 'BoneXa+JBZOh4bKOKgMG4CSv/R2HrftrcSUnuYsg6u8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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