SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba6c777d45447b17cfde160ba6250cff21d6dac170d22aa94c2cf5af3f087962' 
  AND token = 'bWjyky9U7404K+JkaXRN4iUlay/+CmrS2oXkBvLqmYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}