SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75af6cdef829b6676f7a34929997355f6de7153c00c62476d0915d3a9738c723' 
  AND token = 'HmKiIXNRoCCELptxaD3FU6KgNzGA/jnSTqFImQYRcnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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