SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc48fdbe8f7e3a82d6564dbeceed93c9345bf17aba974bfc57ebb9246277fb55' 
  AND token = 'ANgaPh/z5LGQqVRfP1CM9wfppaYgcDzc+Dw+whiOnck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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