SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5848ec77150e4ed433e30ef5f32bc833012ed40e081f28839b888d28df7a9336' 
  AND token = 'HLdnQXMxU2KD5afNh9yGxQcn1v2PnnA1ezH2kOSXoOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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