SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c8c84fe15b8155aee04bf40d3d0e5e514f76c0b91ed24f7883bd3347b3c03c2' 
  AND token = 'Qwc165mYkIuCUrpqfkwx+8+GuUPip00okLM+nTCrTRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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